var obj = null;
var As = document.getElementById('topnav').getElementsByTagName('a');
obj = As[0];
var url = window.location.href;
for (i = 1; i < As.length; i++) {
	if (url.indexOf(As[i].href) >= 0) {
		obj = As[i];
	} else if(
			(url.indexOf('articledetail') >= 0 || url.indexOf('/album') >= 0)
			&& As[i].href.indexOf('/list') >= 0) {
		obj = As[i];
		break;
	}
}
obj.id = 'topnav_current'